Alarm devices for asset protection are typically mounted to the asset and monitor the asset's movement, transmitting an alarm signal if the movement is greater than a factory selected tolerance. As in U.S. Pat. No. 6,724,316 B2, which is incorporated herein by reference, the alarm device monitors the asset's movement by determining if there has been a change in the gravitational field of the sensor with respect to the earth's gravitation field or alternatively if there has been a change in the magnetic field of the sensor with respect to the earth's magnetic field. The alarm device periodically samples the sensed field and compares the samples to a calculated threshold. The calculated threshold is determined from an initial or at rest sample and a factory selected tolerance. The factory selected threshold prevents false triggers such as those that might be caused by noise spikes and the like.
For some assets it may be desirable to move the asset from one location to another within a premises without causing an alarm. An example would be a laptop computer in a library setting. To help with accessibility to their multiple patrons, the library may allow the computer to be moved from one desk to another, but would want to safeguard the laptop computer from being taken from the library. For this situation, it would be desirable for the library to be able to set the time that the asset could be moved so that the laptop computer could travel within the desk area without causing an alarm to sound. Alternatively the library may want to limit the laptop travel area to a section of the library without causing an alarm to sound. The travel distance and time for this situation is different and it would be desirable to customize the allowed travel distance for each situation. Similarly in an office setting, furniture protected by an alarm device may need to be moved within a conference area, but may not be allowed to leave the conference area.
It is therefore an object of the present invention to provide an asset protection device that allows the asset to be moved within a premises while being protected from leaving the premises.
It is also an object of the present invention to provide an asset protection device that allows the time that the asset could be moved to be field programmable to allow for different sized locations.